Package net.sf.saxon.functions

Class FormatNumber

java.lang.Object
net.sf.saxon.functions.AbstractFunction
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.FormatNumber
All Implemented Interfaces:
Callable, StatefulSystemFunction, FunctionItem, GroundedValue, Item, Sequence
public class FormatNumber extends SystemFunction implements Callable, StatefulSystemFunction
Implementation of format-number() function. Note this has no dependency on number formatting in the JDK.

  • Constructor Details

    • FormatNumber

      public FormatNumber()

  • Method Details

    • fixArguments

      public Expression fixArguments(Expression... arguments) throws XPathException
      Allow the function to create an optimized call based on the values of the actual arguments. This handles the case where the decimal format name is supplied as a literal (or defaulted), and the picture string is also supplied as a literal.
      Overrides:
      fixArguments in class SystemFunction
      Parameters:
      arguments - the supplied arguments to the function call
      Returns:
      either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place
      Throws:
      XPathException - if an error is detected

    • makeSubPicture

      protected static FormatNumber.SubPicture makeSubPicture(int[] details, DecimalSymbols dfs) throws XPathException
      Throws:
      XPathException

    • adjustToDecimal

      public static BigDecimal adjustToDecimal(double value, int precision)
      Convert a double to a BigDecimal. In general there will be several BigDecimal values that are equal to the supplied value, and the one we want to choose is the one with fewest non-zero digits. The algorithm used is rather pragmatic: look for a string of zeroes or nines, try rounding the number down or up as appropriate, then convert the adjusted value to a double to see if it's equal to the original: if not, use the original value unchanged.
      Parameters:
      value - the double to be converted
      precision - 2 for a double, 1 for a float
      Returns:
      the result of conversion to a double

    • call

      public StringValue call(XPathContext context, Sequence[] arguments) throws XPathException
      Call the format-number function, supplying two or three arguments
      Specified by:
      call in interface Callable
      Parameters:
      context - the dynamic evaluation context
      arguments - the values of the arguments, supplied as Sequences.

      Generally it is advisable, if calling iterate() to process a supplied sequence, to call it only once; if the value is required more than once, it should first be converted to a GroundedValue by calling the utility methd SequenceTool.toGroundedValue().

      If the expected value is a single item, the item should be obtained by calling Sequence.head(): it cannot be assumed that the item will be passed as an instance of Item or AtomicValue.

      It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.

      Returns:
      the result of the function
      Throws:
      XPathException - if any dynamic error occurs

    • getNamedDecimalFormat

      protected DecimalSymbols getNamedDecimalFormat(DecimalFormatManager dfm, String lexicalName) throws XPathException
      Get a decimal format, given its lexical QName
      Parameters:
      dfm - the decimal format manager
      lexicalName - the lexical QName (or EQName) of the decimal format
      Returns:
      the decimal format
      Throws:
      XPathException - if the lexical QName is invalid or if no decimal format is found.

    • formatExponential

      public static String formatExponential(DoubleValue value)
      Format a double as required by the adaptive serialization method
      Parameters:
      value - the value to be formatted
      Returns:
      the formatted value

    • copy

      public FormatNumber copy()
      Make a copy of this SystemFunction. This is required only for system functions such as regex functions that maintain state on behalf of a particular caller.
      Specified by:
      copy in interface StatefulSystemFunction
      Returns:
      a copy of the system function able to contain its own copy of the state on behalf of the caller.

    • getFormatter

      public static Function<Double,String> getFormatter(String picture) throws XPathException
      Get a function to format a double as a string using a supplied picture
      Parameters:
      picture - the supplied picture
      Returns:
      a function that converts a double to a string
      Throws:
      XPathException - if the picture is invalid